I'm actually surprised that I have found so many jobs that way, compared to how easy it was just knowing some people who already work at the company who is hiring. I still had to interview, though--one interview with the hiring manager and her boss that took less than an hour.
The only problem is that very few of my old colleagues have connections to any of the jobs that I might actually want.
So now the standard response I get is "we decided to hire someone that was a better fit for us" or "we decided not to fill the position at this time". If you can't read the subtext, that means "you're too old (and therefore expensive)" or "we were trying to import someone cheaply, and your application screwed that up."